Transitional metal oxides with lamellar feature are desirable catalysts towards peroxydisulfate (PDS) activation for wastewater treatment. However, the feasibility and mechanism of PDS activation by Cu-Fe bimetallic nanosheets are barely explored. Herein, novel ultrathin Cu-Fe oxide nanosheets (CuFe-OS) were constructed by fast reduction for efficient PDS activation. Assembled by intercrossing nanosheets with about 4 nm thickness, Cu₁Fe₁-OS possessed regular crystal texture, multiple metal–oxygen bonds, and abundant oxygen vacancies, distinguishing from the amorphous Cu-Fe oxide (CuFe-O). Such features of Cu₁Fe₁-OS contributed to a 62.40 % increase of typical organic pollutant (acid orange 7) removal efficiency and 13.47 times improvement of degradation rate constant, compared to Cu₁Fe₁-O. Furthermore, the coupling function of radical and nonradical pathways drove the Cu₁Fe₁-OS activation process, with ¹O₂ and ^⋅O₂⁻ as the primary reactive oxygen species. The ¹O₂ was principally generated from the recombination of ^⋅O₂⁻, manifesting the transformation from radical to nonradical mechanism in the Cu₁Fe₁-OS/PDS system. Abundant oxygen vacancies benefited the generation of ^⋅O₂⁻ and the conversion of metallic ions. The bimetallic synergy in Cu₁Fe₁-OS boosted the reversible redox cycles of Fe³⁺/Fe²⁺ and Cu²⁺/Cu⁺. This work provides a novel strategy of persulfate activation for wastewater remediation and deepens the understanding of coupled radical and nonradical mechanisms.